Steel pipes of lining plastic for water supply is to line the internal wall of steel tube with thermoplastic tube such as polyethylene (PE), heat resisting polyethylene (PE-RT), cross-linked polyethylene (PE-X), polypropylene (PP-R), rigid polyvinyl chloride (PVC-U) and chlorinated polyvinyl chloride (PVC-C) etc. according to conveying medium. Based on CJ/T 136-2001 Steel Pipes of Lining Plastic for Water Supply, the standard is revised according to the improvement, upgrading, development and market actual demand of steel pipe of lining plastic manufacturing engineering in recent years. The main revisions are as follows:

1. The specification is expanded to DN500, besides galvanized steel pipes, the base tube can also use straight seam welding steel pipes, spiral seam submerged-arc welding steel pipes and seamless steel pipes, and it also stipulated standards and requirements shall be implemented for all kinds of base tubes;

2. Based on the original external hot galvanizing steel pipes of lining plastic for external corrosion prevention, external coating plastic steel pipes of lining plastic are added, and it also stipulated standards and requirements shall be implemented for all kinds of external corrosion prevention;

3. Stipulate the applied range of all kinds of lining plastic and the standards and requirements shall be implemented for lining plastic and adhesives;

4. The wall thickness and permissible deviation of external coating layer and welded flange coating layer is added;

5. Pretreatment requirements for steel pipes of lining plastic are added;

6. Required value of bond strength of cold water pipe is improved;

7. Test requirements and test methods for hydraulic pressure test are added;

8. Test method for thickness of external coating layer is added;

9. Requirements and test methods for peel strength of external coating layer are added.

Annex A of the standard is informative annex, and annex B is normative annex.

The standard is revised basing on the standard JWWA K116-2004 Steel Pipes of Lining Rigid PVC for Water Supply of Japan Water Works Association; the wall thickness and tolerance of lining plastic layer, requirements and test methods for bond strength test, flattening test and bending test, and inspecting regulations for steel pipes of lining plastic in the standard apply the regulations in JWWA K116-2004.The regulations on varieties of lining plastic, specifications for diameters and types of base tube are enlarged than that in JWWA K116-2004, and the bond strength value is improved.

The standard was proposed by the Research Institute of Standards & Norms at the Ministry of Construction of PRC.

The standard has been given by the Ministry of Construction of PRC to the Drainage Department Technical Standard and Norms Committee for verification.

The standard is drafted by Shanghai Xintian Industrial Co, Ltd., Shanghai Deshi Water Cleaning Pipeline Manufacture Co., Ltd., Shanghai (Zhuhai) Ganghua Piping System Development Co, Ltd., Jin Zhou Group Co, Ltd., Tianjin Lida Steel Pipe Group Co., Ltd., Guangzhou Xiangji Compound Steel Pipe Co, Ltd., Guangdong Walsall Steel Pipe Industrial Co., Ltd., Tianjin Youcheng Galvanized Steel Pipe Co., Ltd., Benxi Economic Development Area Benxi Tianhe Steel Pipe Co, Ltd., and Hangzhou Chunyuan Steel Plastic Tube Co., Ltd.

The drafters are:        Qian Lezhong, Teng Wanbo, Tang Sunqing, Jiang Jianming, He Yanxiong, Shen Ganrong, Xu Deru, Yu Fuqiang, Yu Lixin, Chen Caiji, Luo Penghua, Deng Jinxiang, Li Xueren, Wu Ping, Jiang Yanbo, Chen Zhen, and Fan Xiaomin.

 

This standard prescribes the scope, product classifications and marks, material, requirements, test methods, inspection regulations, symbol, packing, transportation and storage of steel pipes of lining plastic for water supply (short for steel pipes of lining plastic).

The standard is suitable for steel pipes of lining plastic for water supply with nominal diameter no larger than 500mm, mainly used for delivering domestic hot/cold water. Medium for other purposes can refer to it.

Terms in the following references become terms of this standard through quotation. For dated references, the afterwards revision (not including corrigendum) or the revised edition are not applicable to this standard. However, the agreements achieved within all professional institutions are encouraged that the latest version of these documents can or cannot apply to the standard. For undated references, applies the latest edition of the publication.

GB/T 24l Metal Tubes--Hydrostatic Pressure Testing Methods

GB/T 244 Metallic Materials--Tube--Bend Test Methods

GB/T 246 Metal Materials-Tube - Flattening Test Methods

GB/T 2102-1988 Acceptance, Packing, Marking and Quality Certification of Steel Pipe

GB/T 309l Welded Steel Pipe for Low Pressure Liquid Delivery

GB/T7306.2 Sealed Pipe with 55° Thread Angle --Part 2: Taper Internal and External Threads

GB/T 8163 Seamless Steel Pipes for Liquid Delivery

GB/T 9119 Slip-on-welding Plate Steel Pipe Flanges with Flat Face or Raised Face

GB/T 9124 Specification for Steel Pipe Flanges

GB/T 9711.1 Petroleum and Natural Gas Industries-Steel pipe for Pipelines-Technical Conditions for Delivery -Part 1: Class A Steel Pipes

GB/T 10002.1 Unplasticized Polyvinyl Chloride (PVC-U) Pipe for Water Supply

GB/T 12611 Technical Requirements of Quality Control for Metal Parts before Being Coated

GB/T 13295 Ductile Iron Pipes, Fittings and Accessories for Water or Gas Applications

GB/T 13663 Polyethylene Pipes for Water Supply

GB/T 15558.1 Polyethylene (PE) Valves for Gas Distribution Systems

GB/T 1721 9 Standard for Safety Evaluation of Equipment and Protective Materials in Drinking Water System

GB/T 17395 Dimensions, Shapes, Masses and Tolerances of Seamless Steel Tubes

GB/T 18742.2 Polypropylene Piping Systems for Hot and Cold Water Installation-Part 2: Pipes

GB/T 18992.2 Cross-linked Polyethylene (PE-X) Piping Systems for Hot and Cold Water Installations--Part 2: Pipes

GB/T 18993.2 Chlorinated Polyvinyl Chloride Piping Systems for Hot and Cold Water Installations--Part 2: Pipes

CJ/T 120 Coating Plastic Steel Pipe for Water Supply

CJ/T 156 Grooved Couplings

CJ/T 175 Polyethylene of Raised Temperature Resistance (PE-RT) Piping Systems for Hot and Cold Water Installations

QB/T 3834 Thickness Testing Method of the Metal Deposits and Conversion Coatings for the Light Industrial Products--Magnetic Method

SY/T 0413 Technical Standard of Polyethylene Coating for Buried Steel Pipeline

SY/T 5037 Spiral Submerged Arc-welded Steel Pipe for Pipelines for Low Pressure Field Fluid

WFJF（2001）No. 161 Specification for Hygienic Safety Evaluation of Water Delivery Equipment and Protective Materials for Drinking Water

According to temperature of delivering water it can be divided into steel pipes of lining plastic for cold water and steel pipes of lining plastic for hot water.

Product mark is composed of code for steel pipes of lining plastic, code for lining plastic and nominal diameter.

图中文字：The unit of nominal diameter is mm;  Code for lining plastic: PE for polyethylene; PE-RT for heat resisting polyethylene;   PE-X for cross-linked polyethylene; PP-R for polypropylene; PVC-U for rigid polyvinyl chloride;  PVC-C for chlorinated polyvinyl chloride;  Code for steel pipes of lining plastic for cold water: SP-C;  Code for steel pipes of lining plastic for hot water: SP-CR;  Code for external coating plastic steel pipes of lining plastic for cold water: PSP-C;   Code for external coating plastic steel pipes of lining plastic for hot water: PSP-CR. 

SP-CR-(PE-RT)-DNl00 means lining heat resisting polyethylene compound steel pipe for hot water with nominal diameter of 100mm.

 

If the base tube applies straight seam welding steel pipe, it shall be in accordance with the requirements for base tube in GB/T 3091;

If the base tube applies spiral seam submerged-arc welding steel pipe, it shall be in accordance with the requirements for base tube in SY/T 5037;

If the base tube applies seamless steel pipe, it shall be in accordance with the requirements for base tube in GB/T 17395;

If the base tube applies petroleum and natural gas industrial delivering pipe, it shall be in accordance with the requirements for base tube in GB/T 9711

If the external corrosion protection of base tube is hot galvanized, it should be in accordance with the requirements for galvanizing coat in GB/T 3091;

If the external corrosion protection of base tube is plastic coating, it should be in accordance with the requirements for coating layer in CJ/T 120

If the external corrosion protection of base tube is external coating plastic, it should be in accordance with the requirements for external coating layer in SY/T 0413.

The size of steel flange welded on base tube shall be in accordance with stipulations in GB/T 9119 or other corresponding standard;

The material of steel flange shall be in accordance with stipulations in GB/T 9124 or other corresponding standard

The size of steel muzzle bell welded on base tube shall be in accordance with stipulations in GB/T 13295.

4.5 If steel pipes of lining plastic apply grooving connection, the external diameter of base tube shall be in accordance with stipulations in CJ/T 156.

The lining plastic of steel pipes of lining polyethylene (PE) for water supply shall be in accordance with the requirements for plastic in GB/T 13663;

The lining plastic of steel pipes of lining polyethylene (PE) for gas supply shall be in accordance with the requirements for plastic in GB/T 15558;

The lining plastic of steel pipes of lining heat resisting polyethylene (PE-RT) for hot and cold water shall be in accordance with the requirements for plastic in CJ/T 175;

The lining plastic of steel pipes of lining cross-linked polyethylene (PE-X) for hot and cold water shall be in accordance with the requirements for plastic in GB/T 18992.2;

The lining plastic of steel pipes of lining polypropylene (PP-R) for hot and cold water shall be in accordance with the requirements for plastic in GB/T 18742.2;

The lining plastic of steel pipes of lining rigid polyvinyl chloride (PVC-U) for water supply shall be in accordance with the requirements for plastic in GB/T 10002.1;

The lining plastic of steel pipes of lining chlorinated polyvinyl chloride (PVC-C) for hot and cold water shall be in accordance with the requirements for plastic in GB/T 18742.2.

The external coating plastic for external coating polyethylene steel pipes shall be in accordance with the requirements for plastic in SY/T 0413.

The adhesives between external coating plastic and steel pipe shall be in accordance with the requirements for adhesives in SY/T 0413, and adhesives between lining plastic and steel pipe shall be in accordance with the corresponding requirement for performance needed for lining material.

4.9.1 The rust, burr and dirt on matrix metal surface shall be removed by shot blasting, burnishing and acid-washing before the base tube being lined, and it shall be in accordance with the stipulations in GB/T 12611.

4.9.2 Collar shall be removed from straight seam welding steel pipe, and the residual height shall not exceed 0.5mm.

5.1.1 Coating thickness of lining steel pipe shall be in accordance with requirements in Table 1.

  Table 1 Coating Thickness and Permissible Deviation           Unit: mm

 

5.1.2 Cut length of lining plastic steel pipes is commonly 6m, and permissible deviation for its full length is ±20mm. Lining plastic seamless steel pipes can be delivered agreement achieved by supply and requisitioning parties.

5.2.1 Both internal and external surface of lining plastic steel pipes shall be smooth and no bubbles, cracks, decrustations, scars, sags, uneven color and decomposition color variation line.

5.2.2 Shape of lining plastic steel pipe shall be straight, both end sections shall be vertical to pipe axis.

5.3.1 Bond strength: the bond strength between steel and lining plastic of lining plastic steel pipe for cold water shall not be less than 0.3MPa (30N/cm²), and that of lining plastic steel pipe for hot water shall not be less than 1.0MPa (100N/cm²).

5.3.2 Bending performance: no cracks shall occur to lining plastic steel pipe with nominal diameter not exceeding 50mm after being bended, and no layer separation occurs between steel and plastic coat.

5.3.3 Flattening performance: no cracks shall occur to lining plastic steel pipe with nominal diameter larger than 50mm after being flattened, and no layer separation occurs between steel and plastic coat.

5.3.4 Hygiene performance: the hygiene performance of lining plastic steel pipe for delivering drinking water shall be in accordance with requirements in GB/T 17219, or according to requirements in WFJF（2001）No.161 of hygiene department.

5.3.5 Heat/cold resisting cycle performance: three cycles of heat cycle test shall be carried out for test specimen of lining plastic steel pipe for delivering hot water, and no deformation, cracks and defection shall occur to lining plastic coat, the bond strength shall not be less than the specified value in 5.3.1.

5.3.6 Hydraulic test

Hydraulic test for base tube shall be carried out according to the standard for base tube, hydraulic test for lining plastic steel tube shall also be carried out when proceeding the type test, and the hydraulic test can either be carried out on the whole steel tube or on test specimen composed by a section of steel tube and pipe fitting, pressure and dwell time of hydraulic test shall be implemented according to standard for base tube.

5.3.7 Peel strength of external coating plastic: the peel strength is required to be no less than 0.35 MPa (35N/m²).

Visual inspection can be used for the appearance of lining plastic steel pipe.

Size of lining plastic steel pipe shall be carried out by vernier caliper with accuracy of 0.02mm, and the size shall be in conformity to the requirements in Table 1. And length of it shall be measured by steel tape. The thickness of external coating shall be inspected according to QB/T 3834 by magnetic method.

Cut out three test specimens with length of20mm from sample pipe randomly, and the length can be changed for 10mm for lining plastic steel pipe with diameter of larger than DN150. See Figure 1, under normal temperature, put the test specimens on test table and gradually bring pressure to lining plastic pipe, at the time of cutting the base tube and lining plastic pipe, measure the pressure value of joint face when separating and work out bond strength according to formula (1), apply the average value of three specimens:

                         F=W/A    ………………………………………………… (1)

                       A=3.14×D×L………………………………………………… (2)

In the formula:

F——N/cm²；bond strength, the unit is N/cm²;

W——separating pressure, the unit is N;

A——area of steel and plastic bond area of lining plastic steel pipe, the unit is cm²;

D——average inside diameter of base tube, the unit is cm;

L——length of specimen, the unit is cm.

图中文字：Load  Sizing block  Specimen  Test table  Lining plastic coat

According to specification in GB/T 244, cut out a section of pipe with appropriate length from sample pipe as specimen. Under normal temperature, put specimen on the mould and bend for 10°， and the radius of curvature of mould is 8 times larger than external diameter. When testing, the specimen carries no filling. After the test, cut specimen from the middle of bending arc and check if visible separation exists between steel and both internal and external plastic coat.

Cut a section of pipe with length of no less than 50mm from any place of finished pipe as specimen according to GB/T 246.

Under normal temperature, clamp specimen between two parallel boards as Figure 2 shows, make welding joint of straight seam welding steel pipe 90°with its load, then bring pressure to the boards till the specimen is pressed to be 3/4 of its external diameter, check if visible separation exists between steel and both internal and external plastic coat.

图中文字：Load    Steel pipe   Lining plastic coat   3/4 external diameter   Welding joint

The test shall be carried out according to either the stipulations in GB/T 17219 or test method stipulated by stipulations of WFJF（2001）No. 161.

Dip a specimen with length of 200mm into hot water with temperature of 95℃±2℃ for 30min, and put 10mm of it under normal temperature for natural cooling after taking it out, dip 30mm of it into cold water with temperature of 5℃±2℃, then take out and put it under normal temperature for 10min, all of the above forms one cold/heat cycle, and three cold/heat cycle shall be carried out totally. After that, cut the middle section of specimen for 20mm to carry out bond strength test according to stipulations in 6.3.

Carry it out according to stipulations in GB/T 241.

The peel strength shall be measured according to stipulated test method in annex B.

Inspection for lining plastic steel pipe contains delivery inspection and type inspection.

Batch planning and sampling of lining plastic steel pipe shall be carried out according to requirements in Table 2.

 

7.2.1 Lining plastic steel pipe can only leave factory after being inspected to be qualified by quality inspection department of the factory.

7.2.2 The delivery inspection items and numbers of sampling shall be in accordance with stipulations in Table 2.

7.2.3 For each inspection item, if one piece is tested to be unqualified, pick it out and take double specimens for retest, if either of them is still unqualified, then the whole batch shall be regarded as unqualified. However, the supplier can pick out the qualified ones from that batch to form a new batch for inspection.

7.3.1 Type inspection can be carried out under the following conditions:

a) Product approval;

b) Great changes that may affect product performance happen to the design, technology and material of product;

c) Being put back into production after half year of stop production;

d) Regular production reached one year;

e) National quality supervision and inspection institute requires for type inspection.

7.3.2 Type inspection items:

For lining plastic steel pipe for hot water, the inspection items are items stipulated in requirements of this standard other than items in 5.3.7.

For lining plastic steel pipe for cold water, the inspection items are items stipulated in requirements of this standard other than items in 5.3.5 and 5.3.7.

For external plastic coating steel pipe, tests in 5.3.7 shall be carried out besides the above two stipulations.

Lining plastic steel pipe for delivering drinking water, tests in 5.3.4 shall be carried out besides the above three stipulations.

7.3.3 Specimen of type inspection shall be randomly chosen from qualified batches approved during delivery inspection.

7.3.4 If hygiene performance is unqualified during type inspection, then the whole batch shall be regarded as unqualified and no reinspection needed.

For other items, if one piece or one item is inspected to be unqualified, double the numbers of specimen, and carry out reinspection for unqualified items. If it’s still inspected to be unqualified in reinspection, the whole batch shall be regarded unqualified for type inspection.

8.1.1 The external surface of lining plastic steel pipe shall be tagged with product mark, manufacturer’s name, lining plastic steel pipe and executive standard No.

8.1.2 Internal lining plastic pipe of lining plastic steel pipe for delivering cold water shall be white (natural color) and red lining plastic pipe for lining plastic steel pipe for hot water.

Packing shall be carried out according to item 2.1 in GB/T 2102-1988, with both ends of compound pipe enveloped. Two certificates of quality shall be hung or tagged to each batch, and indicate the following contents: product trade mark, product name, quantity, batch No., lining plastic steel pipe and executive standard No. of base tube, manufacturing date, and manufacturer’s name, address and telephone No.

No falling or serious bump shall occur to lining plastic steel pipe during transportation.

Lining plastic steel pipe shall be straightly stacked in the shade and keep away from heat source and tinder, long-term of stacking exposed to outdoor sunlight or at frigid places is not allowed.